1. Field of the Invention
The present invention relates generally to mobile communications systems, and more specifically to a personal mobile telephone system distinct from automobile telephone systems.
2. Description of the Related Art
Mobile telephone systems which have been proposed for servicing personal (handset) mobile stations are of two types. One is the type of system which is similar to the conventional cellular automobile telephone system where the location of each automobile is identified at all times by the system, and the other is a simplified, low-cost system which involves the use of a paging station as a means for directly paging a mobile station in the same manner as it pages the usual radio paging users. In the former case, the system would require some procedure for making a registration of a personal mobile station. A database for storing the positions of individual mobile stations and a dedicated switching system would be needed for this purpose. A call to a mobile station from the public switched telephone network would need an access to the database to determine in which zone (cell) the mobile station is currently located and then establish a connection through the dedicated switching system to the destination. This represents a significant burden on land lines, system complexity and a substantial amount of investment. In the latter case, the personal mobile unit would be designed so as to integrate its telephone functions with the functions of a radio pager. On receiving a page from a network user, the mobile user would know the telephone number of the calling party and call back the network user by dialling the paged number. However, a number of disadvantages are apparent; the mobile user needs to call back the network user, and the necessity to combine the telephone and paging functions results in an unnecessary cost and a bulky design.